A brief history of 3D printing

Posted on by aneczka2307

http://ottawacitizen.com/news/local-news/the-evolution-of-3d-printing

A 3D printer used by a clinic in France to create skull and facial implants.

A brief history of 3D printing

On that evening, more than three decades ago, when he invented 3D printing, Chuck Hull called his wife.

She was already in her pyjamas, but he insisted that she drive to his lab to see the small, black plastic cup that he had just produced after 45 minutes of printing.

It was March 19, 1983. Hull was then an engineer working at a U.S. firm that coated furniture with a hard plastic veneer. As part of his work, he used photopolymers — acrylic-based liquids — that would solidify under ultraviolet light. Hull thought the same sort of process might be used to build a three-dimensional object from many thin layers of acrylic, hardened one after another, with targeted UV light from a laser beam.

Hull pursued his research on nights and weekends until finally sharing his eureka moment with his wife, Anntionette.

“I did it,” he told her simply.

Chuck Hull, inventor of the 3D printer

Hull took out a series of patents on his invention and went on to co-found a company, 3D Systems, that remains a leader in the field. Last year, the 75-year-old was inducted into the National Inventors Hall of Fame.

Hull’s invention launched a wave of innovation. Design engineers embraced 3D printers as the answer to their prayers: Instead of waiting weeks or months to have new parts produced, they could design them on computers and print prototypes the same day.

3D printers have since evolved and can now use all kinds of materials, including metals, ceramics, sugar, rubbers, plastics, chemicals, wax and living cells. It means designers can progress rapidly from concept to final product.

Advances in the printers’ speed, accuracy and versatility have made them attractive to researchers, profit-making firms and even do-it-yourselfers.

The cost of the machines has also dropped dramatically, which means it’s easy for home inventors to enter the field. Home Depot sells a desktop version for $1,699 while Amazon.com markets the DaVinci Junior 3D printer for $339.

The machines have been used to print shoes, jewellery, pizza, cakes, car parts, invisible braces, firearms, architectural models and fetal baby models (based on ultrasound images).

The wave of innovation triggered by the 3D printer is only now beginning to crest in the field of medicine. Researchers are racing to engineer implantable livers, kidneys and other body parts with the help of 3D printers.

In Canada, scientists are using 3D bioprinters as they work toward creating new limb joints made from a patient’s own tissue, and implantable skin for burn victims.

ottawacitizen.com

by Andrew Duffy | August 28, 2015 2:00 PM EDT

3D printed ‘super batteries’ from graphene ink!

Posted on by aneczka2307

http://www.wired.co.uk/news/archive/2015-08/10/graphene-3d-printed-super-batteries

‘Super batteries’ to be 3D printed from graphene ink

Manchester Metropolitan University is embarking on a project to 3D print “super batteries” from graphene ink.

Wonder material graphene has been widely talked about in terms of its suitability for use in batteries, due to its impressive conductivity, but scientists have struggled with the fact it also has a relatively small surface area, which affects capacity.

3D printing, where layers of graphene are assembled on top of one another, maximising surface area in the process, offers a solution. Now researchers at MMU are analysing techniques for printing with conductive graphene ink, in order to try and create batteries, supercapacitors and other energy storage devices with the help of a grant from the Engineering and Physical Sciences Research Council.

“We’re trying to achieve a conductive ink that blends the fantastic properties of graphene with the ease of use of 3D printing to be manipulated into a structure that’s beneficial for batteries and supercapacitors,” explains Craig Banks, a professor of electrochemical and nanotechnology and leader of the three and a half-year project. The batteries and supercapacitors would be used to power phones and tablets, or for solar, wind and wave power storage.

“Energy storage systems (ESS) are critical to address climate change and, as clean energy is generated through a variety of ways, an efficient way to store this energy is required,” says Banks, whose work on graphene’s conductivity has been cited over 9,000 times, making him one the world’s most-cited scientists. “Lithium and sodium ion batteries and super/ultracapacitors are promising approaches to achieve this. This project will be utilising the reported benefits of graphene — it is more conductive than metal — and applying these into ESS.”

The combination of the conductivity from the graphene and the 3D nature of the structures, which have “high surface areas, good electrical properties and hierarchical pore structures/porous channels”, should increase the storage capabilities of batteries to meet future demands.

As well as working on the graphene ink, the 3D printing process also must be refined. It currently relies on each layer of graphene being left to “cure” for an hour before the next layer can be applied. Banks is hoping to find a method to speed this process up, perhaps by using UV light. “Ideally, we could have the brilliant scenario where you just plug in and go — printing whatever structure you want out of graphene from a machine on your desk,” he says.

Graphene was discovered in 2004 at the University of Manchester, which has recently become the home of the National Graphene Institute — a £61 million building to house the university’s groundbreaking work. This particular research will be taking place at MMU rather than at the University of Manchester, but it is yet another project that shows the city remains a world-renowned centre for research graphene.

wired.co.uk

by KATIE COLLINS | 10 AUGUST 15

3D printing color

Posted on by aneczka2307

http://mashable.com/2015/06/19/3d-printing-color/

3d-prints

3D printing has been taken to a whole new level: Color

3D printing is driving a huge revolution in the world of design and technology. In the process, it is changing the way we think about the design, prototyping and manufacturing of just about everything.

But anyone who has played with a 3D printer will be aware of one significant problem. This 800-pound gorilla is the issue of color. 3D prints can be magnificent copies of more or less any shape. But in terms of color, they are mere shadows of the originals.

Today, that looks set to change thanks to the work of Alan Brunton and pals at the Fraunhofer Institute for Computer Graphics Research in Germany, who have worked out how to produce accurate colors in a 3D print for the first time. Their work promises to take 3D printing to an entirely new level.

The approach takes advantage of a relatively new way to make 3D prints. In general, these objects are made one layer at a time by fusing powder or laying down extruded plastic. Neither approach gives anything but rudimentary control over an object’s color.

What’s needed instead is a way of creating objects in the same way as 2D printers make images, pixel by pixel. In other words, this requires 3D prints to be laid down, not in layers, but voxel by voxel.

In the last year or so, exactly this technology has come to market. It works using a number of inkjets that lay down an object, droplet by droplet. These droplets are instantly cured by UV light to form a solid.

That immediately allows the possibility of much more accurate control of color, since each droplet can be thought of as a voxel. This is the approach that Brunton and pals have taken, but it is easier said than done for a number of reasons.

The first is the sheer volume of data and number crunching involved in creating a virtual color 3D object, even before the printing begins.

The droplets from inkjets are tiny — there are some 18 million of them in a solid cubic centimeter. So any decent-sized object must be made up of tens of billions of voxels and the impact that each one has on the final color has to be calculated.

The second is that the droplets are translucent because UV light must be able to pass through to cure them. This has a significant impact on their visual appearance since light ends up passing through several layers of voxels, being scattered along the way.

That means droplet color has to be carefully controlled to a depth of several voxels throughout the object. And this dramatically increases the complexity of the algorithms needed to calculate their required colors.

The final challenge comes from the nature of 3D printing. In 2D printing, it is possible to combine up to three different inks at any point on an image. In a 3D print, each droplet must be a single material and that places important constraints on what is possible colorwise.

Nevertheless, Brunto and co have made significant advances by bringing to bear the many decades of research that has been done on color management for 2D printing and for color imaging in general.

Their approach is to combine two techniques. The first is the 3D equivalent of a 2D printing technique called half-toning. This is where continuous shade and color is replaced by an arrangement of dots of different sizes and spacing. The second is a way of calculating the color of a surface given the way light has been scattered for several layers of voxels below.

And the results look impressive. In the pictures above, three apples and the thumb are real. The rest are 3D prints but it is not easy task to tell them apart.

And Brunton and co say the results should get better in the near future as materials scientists develop less translucent printing materials and as printers become even higher resolution. In both these respects, the team’s algorithms are future proof. Less translucent inks should be easier to handle and the higher resolution should be manageable too.

The ability to combine translucent and opaque inks should even make it possible to reproduce the surface appearance of many biological materials that are also semi-translucent, such as skin.

That’s fascinating work. It will usher in a new generation of printing application. And it will make the current generation of printers look thoroughly old-fashioned in just a few years.

References:

mashable.com

http://mashable.com/2015/06/19/3d-printing-color/